The objectives of this proposed project are as follows: (1) To determine the nucleotide sequence of specific operator and promoter sites on bacteriophage DNA molecules. (2) To chemically synthesize lactose operator DNA, and to study the specific interaction between lactose repressor and lactose operator. (3) To develop and to improve methods for DNA sequence analysis so that the objectives listed above can be achieved more readily. BIBLIOGRAPHIC REFERENCES: Itakura, K., Kategiri, N., Narang, S.A., Bahl, C.P., Marians, K.J. and Wu, R., Chemical Synthesis and Sequence Studies of Deoxyribonucleotides which Constitute the Duplex Sequence of the Lactose Operator of E. Coli, J. Biol. Chem. 250, 4592-4600, 1975. Ghangas, G.S. and Wu, R., Specific Hydrolysis of the Cohesive Ends of Bacteriophage lambda DNA by Three Single-Strand Specific Nucleases, J. Biol. Chem. 250, 4601-4606, 1975.